Common Rail Fuel Injection System (Crdi); Low Pressure Fuel Circuit; High Pressure Fuel Circuit; Low Pressure Fuel Pump - Hyundai Seasall S250S Workshop Manual

Fuel System

Common Rail Fuel Injection System (CRDI)

Pump Pump
pressure pressure
regulator regulator
valve valve
Fuel Fuel
temperature temperature
sensor sensor
Water in fuel Water in fuel
sensor sensor
Feed Feed
pump pump
Fuel tank Fuel tank

Low Pressure Fuel Circuit

Low Pressure Fuel Pump

The low pressure fuel pump is either an electric fuel
pump with pre-filter, or a gear-type fuel pump. The
pump draws the fuel from the fuel tank and continually
delivers the required quantity of fuel in the direction of
the high pressure fuel pump (via fuel filter).
Fuel Filter
The fuel filter is located in between the low pressure
fuel pump and the high pressure fuel pump and filters
the fuel delivered from the fuel tank.

High Pressure Fuel Circuit

High Pressure Fuel Pump
The high pressure fuel pump compresses fuel up to
1,600 bar and delivers the compressed fuel to the
common rail
Common Rail
The two common rails are installed on bank 1 and 2
and are connected with the high pressure fuel pump
and the injectors by the high pressure fuel pipes. This
return return
High High
pressure pressure
pump pump
Main Main
fuel fuel
filter filter
return return
134
Common rail Common rail
return return
return return
Injector Injector
Fuel feed (low) Fuel feed (low)
Fuel return Fuel return
Fuel feed (high) Fuel feed (high)
rail stores the fuel compressed in the high pressure fuel
pump. So that the two rails have same fuel pressure,
the high pressure fuel pipe connects the two rails. The
ECM controls the fuel pressure of the common rail by
using the rail pressure sensor and the rail pressure
regulator valve installed on the common rail (Bank 1)
and (Bank 2) respectively.
Injector
The injector injects the high pressure fuel stored in the
common rail into the cylinder by the ECM control signal.
High Pressure Fuel Pump
The high pressure fuel pipe is a channel in high
pressure fuel circuit consisting of the high pressure fuel
pump, common rails, and injectors. It is a steel tube
which can withstand high frequency generated when
the fuel pressure reaches the maximum pressure or
fuel injection stops.
The differences in length between the common rail and
the individual injectors are compensated for by using
slight or pronounced bends in the individual lengths of
tubing. Nevertheless, the injection lines should be kept
as short as possible.
Fuel Delivery System
Rail pressure Rail pressure
sensor sensor
Rail Rail
pressure pressure
regulator regulator
valve valve